He carries the trait, but didn't know it till his son was born with it, too.

People with the trait don't have the disease, but when two carriers have a child, there's a 25% chance the baby will develop it.

1 out of every 500 African Americans has the disease - approximately 100,000 across the United States.

In addition to African-Americans, sickle cell is also in those with Caribbean, Greek, Sicilian, Asian, or Turkish ancestry.

Although newborns are routinely tested for it, Gamble urges adults to be tested, too.

"Find out whether or not you have the trait, find out your status. And it's nothing to be ashamed of. It's something that you can help prevent your children and your children's children, from having sickle cell disease," he told Action News.

Saturday's walk will support 17,000 in Pennsylvania with the disease.

"The money will be supporting the families and the individual we serve in terms of transportation, advocacy, newborn screening follow-up, support groups," says Zemoria Brandon.

She is the administrator for the Philadelphia branch of the Sickle Cell Disease Association, and widow of Walter E. Brandon, for whom the walk is named.

He died of sickle cell disease.

"Most people don't know to get tested, unless it runs in their families," says Brandon.